Provided are a transmitter, a receiver and methods of padding and depadding zero bits to an L1-post signaling. The transmitter includes: a zero padder configured to divide an information word into a plurality of groups, pad zero bits to at least one of the plurality of groups by group unit, and pad additional zero bits to at least one of the plurality of groups remaining after the zero bits are padded, thereby constituting the information word for encoding the L1-post signaling; and an encoder configured to perform encoding on the information word for encoding the L1-post signaling. The zero padder pads the additional zero bits according to a predetermined criterion, starting from a front end or a back end of the at least one of the remaining groups.